In one form of balancing machine for balancing a rotary member such as a motor vehicle wheel, the rotary member is carried on a measuring spindle which is brought up to a measuring speed of rotation by means of a hand crank. The balancing machine further includes an assembly for retarding the measuring spindle, for example, after the measuring run has been carried out, that assembly comprising two brake discs of which the first is non-rotatably connected to the measuring spindle while the second brake disc is fixed in the braking operation in a position which is stationary relative to the frame structure of the machine.
However, difficulties are encountered in fixing the second brake disc in its stationary position relative to the frame structure of the machine, by means of a suitable engagement arrangement.